The game is not region locked. We've tested matches with people 10,000 miles away. Steam's browser list matchmaking does return a list of results prioritized by region to give you preference to better matches, but if you've got a friend far away, have them shoot you a game invite.

This is not good. For me it looks like the lobby is dead, at most I can find around 10 matches, even though I know there are people in other regions hosting scenarios I want to play, but I simply can't find them.